Japanese Patent Publication Tokukou-Hei 1-49496 discloses, as an example of conventional vibrator of this type, a vibrator in which an arm having a pair of treating elements is swingably driven around a main shaft to carry out massaging treatment with the intensity being changed by changing the angle of the arm around the main shaft.
Japanese Utility Model Publication Jikkai-Shou 56-125232 discloses a vibrator in which a pair of massaging rings is swingably attached eccentrically to a first rotation shaft in a tilted manner, a pair of massaging elements is attached to the tip of an arm that is swingably attached to the first rotation shaft through an eccentric cam disc, and the tip of a lever is swingably attached to a second rotation shaft through an eccentric cam disc being supported by a frame in the middle of the above-mentioned arm. In this vibrator, the amount of protrusion of the massaging elements attached to the arm through the lever is changed by adjusting the rotation angle of the eccentric cam disc attached to the second rotation shaft so that the pair of massaging rings or both the pair of massaging rings and the pair of massaging elements are made to contact a human body.
Japanese Patent Publication Tokukou-Shou 61-44027 discloses a vibrator in which a pair of ring members that are attached to a main shaft eccentrically and a side lifting roller are installed and the amount of protrusion of the ring members is changed by rotating the main shaft to adjust the strength so that only the ring members or both of the ring members and the side rising roller are made to contact a human body.
These prior art vibrators have the following problems.
(1) Since the treating unit with treatment elements is caused to shift only along a guide, it is not possible to carry out treatments in accordance with the body shape of the user and, depending on positions of the treating unit, the treating elements tend to separate from the treatment subject portion, thereby weakening the strength to be exerted on the treatment subject portion, or the treating elements are too close to make the force exerting on the treatment subject portion too strong.
(2) When no treatments are being carried out, the treating elements form cumbersome objects.
(3) In general, since the distance between the treating elements and the human body is fixed, it is not possible to carry out treatments with a sufficient strength suitable for the condition and the corresponding portion. Although there are vibrators with which the distance between the treatment elements and the human body is adjustable, the amount of adjustment that can be made is small.
(4) It is not possible to achieve a stimulation-type work such as a finger-pressure therapy.
(5) Pounding stimulation onto the human body can be done only in a fixed operation direction and hence is monotonous.
(6) The number of treating elements that can be made to contact the human body is fixed, and this makes the stimulation monotonous.
The present invention has been accomplished in view of these problems, and its objective is to provide a vibrator, a vibration unit and a vibrator control method, which can properly control a force to be exerted on a treatment subject portion by increasing the amount of adjustment of the distance between the treating elements and the human body so that treatments are carried out with strength suitable for the condition and the corresponding portion and so that it is possible to achieve treatments with various functions and to prevent the treating elements to be cumbersome when no treatments are applied.